Read Ebook: A system of practical medicine. By American authors. Vol. 5 by Pepper William Editor Starr Louis Editor

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Toxic narcosis, from opiates, morphia, chloral, etc., are often difficult of diagnosis, except that from opiates and morphia, in which extremely slow respiration and contracted pupils, with lowered temperature, point at once to the cause.

In studying cases of coma all the above-enumerated symptoms should be considered as of great negative or positive value: often the diagnosis is only made by exclusion. The Cheyne-Stokes respiration, pupillary variations, differences in pulse-rate and volume, are present in such varied conditions, irrespective of the nature of the lesion, as to render them of minor value in differential diagnosis.

DOUBLE CONSIOUSNESS is a rare condition, in which the subject appears to have separate forms or phases of consciousness, one normal, the other morbid. This occurs in hypnotic and somnambulic states, probably also in certain cases of insanity and epilepsy. The current of normal consciousness is suddenly broken; the patient enters into the second or abnormal state, in which he acts, writes, speaks, moves about with seeming consciousness; but after a variable time a return to normal consciousness reveals a break in the continuity of the memory: the patient has no recollection whatever of what he did or said in the morbid period. In the hypnotic state subjects may show increased power of perception, and are strangely susceptible to suggestions or guidance by the experimenter. In a second attack the patient often refers back to the first, and does things in continuation or repetition of what he previously did, apparently taking up the same line of thought and action. The morbid states, long or short, are joined together by memory, but are wholly unknown in the normally conscious states. In other words, the patient leads two separate lives, each one forming a chain of interrupted conscious states. In epilepsy we observe remarkable breaks in normal consciousness: the patient goes through certain acts or walks a distance or commits a crime in a dream-like state, and suddenly, after the lapse of a few minutes, hours, or days, becomes normally conscious and has no recollection of what he did with such apparent system and purpose during the seizure. It might, perhaps, be as well to classify these phenomena under the head of amnesia. A case is on record where a man travelled, seeming normal to fellow-travellers, from Paris to India, and who was immensely astonished on coming to himself in Calcutta. Many murders have been committed with apparent design and with skill by epileptics, who upon awaking from their dream-like state were inexpressibly horrified to hear of their misdeeds.

AMNESIA, or loss of memory, may vary in degree from the occasional failure to remember which is allowed as normal, to the absolute extinction of all mental impressions or pictures. This word and the expression memory are here used in a restricted sense, reference being had only to purely intellectual and sensorial acts related to intellection. If we take the general or biological sense of the term memory as meaning the retention of all kinds of residua from centripetal impressions and of motor centrifugal impulses, including common sensory and visual impressions, special sense impressions, all unconsciously received impressions, emotional, intellectual, and motor residua, we should consider amnesia in a correspondingly general way. This, however proper for a physiological study, would be far too complex and premature for an introduction to practical medicine. Recognizing memory, therefore, as a universal organic attribute--a capacity to retain impressions--we will treat of it only in the commonly-accepted sense referred to supra.

Failure of memory may be real or apparent. In the latter sense amnesia is induced by diversion of the attention into a channel different from that in which the line of inquiry is conducted. A normal example of this is seen in the state known as preoccupation, where a person intent upon a certain thought or action forgets who is about him, where he is, and if asked questions fails to answer or answers incorrectly. In pathological states, as in acute curable insanity, apparent loss of memory is often caused by the domination of an emotion or of delusions. In both cases, if the subject can be roused or brought to himself, he remembers all that we inquire about and is amused at his previous false answers or silence. Real amnesia consists in the actual blotting out of recollections or residua in a partial or general manner, for a time or permanently. These differences serve as the basis of a complicated subdivision of amnesia which it is not necessary to fully reproduce here.

Temporary partial amnesia is a variety which is frequently observed in normal persons, even the most gifted. A word or fact escapes us, seems wholly lost for a few minutes, hours, or days; the more we strive to recall it, the less we succeed; yet later, when not sought for, the fact or word appears in our consciousness as if spontaneously, but more probably by some effect of the law of association. Such partial and momentary forgetfulness may assume proportions which render it pathological. What is known as transitory aphasia may be classed in this group. In a few minutes or hours a person without apoplectic, epileptic, or paralytic phenomena loses all power to express his thoughts by speaking or writing; there is verbal amnesia and agraphia. The subject is conscious of his condition and of the wholly futile or incorrect attempts he makes to communicate with others.

Temporary complete amnesia is almost equivalent to loss of consciousness, yet not strictly so. For example, after a sharp blow upon the head a person may perform complicated acts, reply to questions, and apparently act normally, yet after a variable time he will declare that he remembers absolutely nothing of the injury and what he did or said for hours or days afterward. The same phenomenon is observed in the course of psychoses, neuroses , in some acute diseases, and in certain states of intoxication.

Permanent partial amnesia occurs in states of dementia, such as senile dementia, paralytic dementia, and in certain cases of aphasia. Great gaps exist in the patient's memory; some things are well recalled, others wholly and for ever effaced. The psychological law governing the failure of memory in these cases is that the earliest and strongest impressions survive, while recent and less forcible ones are lost. Substantives or names are especially liable to obliteration, as are also many of the delicate residua which lie at the basis of the subject's ethical conceptions and acts.

Permanent complete amnesia is observed at the end of degenerative cerebral diseases, as organic dementia, whether of the form termed secondary or that designated as paralytic. Sometimes after acute general diseases the memory may be a perfect blank for a considerable length of time, and education has to be repeated. Memory may be so completely absent that cases are known in which the patient gave a fresh greeting to the asylum physician every two or three minutes indefinitely, as if each were a first meeting. Momentary perception and automatic response are there, but no impression is made; there is no residuum left in the cortical centres. In these cases amnesia is accompanied by degeneration of the visual, auditory, etc. cortical areas or centres.

An interesting form of amnesia, not generally recognized as such, is the loss of acquired skill in muscular movements, such as are necessary for writing, for using tools, and for doing various delicate professional movements. Here the motor residua acquired by laborious education or training are gradually lost without actual paralysis or ataxia. This variety is exquisitely illustrated by certain cases of dementia paralytica where long before marked intellectual symptoms occur there is loss of skill in mechanical arts and in handwriting.

In testing a subject's memory due attention should be paid to the law of the survival of older and more interesting residua, as well as to the power of the law of association. Such questions should be asked as pertain to recent events in the patient's experience, and about matters which are not closely related logically. A patient who might tell us nearly all about his early personal experiences, his business and family relations, incidents of his childhood, etc., would fail to remember what he had for breakfast, what he did the day before, etc.

The physiological cause of real amnesia is impairment in the vitality of ganglion-cells in the various cerebral sensory areas or centres, and of the motor area as well . In cases of transitory amnesia we suppose this to be due to the action of toxic agents, to anaemia, and impaired molecular or chemical nutrition, as after acute diseases, in extreme debility, in psychoses, etc. In cases of terminal permanent dementia, autopsies afford us evidence of degeneration and disappearance of ganglion-cells: we find granular and fatty pigmentation, atrophy, calcarous degeneration of these bodies, thickening and shrinkage of the neuroglia, and degenerative changes in blood-vessels. Doubtless degeneration or destruction of association fasciculi of nerve-fibres in the cortex cerebri or in the white substance plays a considerable part in the production of permanent amnesia, but we are as yet unable to give a clear demonstration of this. Theoretically, we may admit an organic loss of memory with the following conditions of the brain: diseased perceptive centres or motor area with normal association fasciculi; normal perceptive centres and motor area with degenerate or broken association fasciculi, connecting these parts with one another and with the more strictly ideational or expressive areas and parts of the brain and spinal cord.

Amnesia--or, more properly speaking, dulness of perception and feebleness of retention of residua--occurs as a strictly congenital condition from imperfect cerebral development, or a little later in life from infantile diseases, constituting one of the aspects of idiocy.

WORD-DEAFNESS is a special morbid psycho-sensory state in which the sounds of language lose their significance for the patient. The sense of hearing is preserved for common sounds, and even music in certain cases; words are heard, but not understood. A patient of mine having this symptom used to say, "If I go to a lecture or hear a sermon, I hear the speaker, but what he says is all Greek to me." On the other hand, this gentleman could go to a concert and understand the musical notes. This condition occurs as a part of the symptom-group aphasia, or it may show itself independently in the course of limited cerebral cortical degenerations. The lesion causing word-deafness is usually found in the left hemisphere, in the first and second temporal gyri, or it may be in the inferior parietal lobule and gyrus supra-marginalis, penetrating deeply enough to injure fasciculi going into the temporal lobe. It would appear, from the evidence now before us, that the centre for psychic hearing is in the caudo-dorsal part of the temporal lobe.

WORD-BLINDNESS, or alexia, is another special morbid psycho-sensory state, in which the visible signs of language lose their significance for the patient. Usually there is no impairment of sight; the patient can see the letters and words as objects, but he cannot read them at all, or must do so letter by letter. Even numerals and pictures of objects in some cases become unintelligible. In testing for this condition a possible confusion with verbal amnesia must not be forgotten. In such a case the patient knows the word or object, but cannot name it; usually he can, however, inform us by signs or indirect expressions that he takes proper cognizance of the object. Alexia is present in a certain proportion of cases of aphasia, and it may be complicated with lateral hemianopia. The exact seat of the lesion producing alexia is at present unknown. Theoretically, however, we must place it in the course of paths from the cortical visual area to the general speech-centre. Psychic blindness for objects in general is now quite conclusively proved to be due to degeneration of both occipital lobes, more especially their mesal gyri, where the visual centres are. This psycho-sensory state, with the accompanying cortical changes, has been demonstrated in cases of dementia paralytica.

APHASIA, or loss of the faculty of language, is so important a symptom as to deserve elaborate consideration in a separate article of this volume; and to it the reader is referred. Suffice it here to state that aphasia may be classified into three forms: Sensory aphasia, in which there is primary disorder of the psycho-sensory part of the complex central mechanism for speech; Motor aphasia , in which the primary lesion affects the motor parts of the mechanism; Amnesic aphasia, in which loss of memory of words and signs is the prime condition.

HYPERAESTHESIA is a condition of exalted excitability in the various parts of the sensory apparatus: terminal nervous organs, nerve-trunks, central gray matter. We may admit such a state as existing independently of consciousness, as where a lesion cuts off communication between the perceptive cerebral centres and the periphery, but in practice we consider only conscious hyperaesthesia. In this state the subject may be able to perceive slighter impacts than would affect a normal individual, or he receives an exaggerated, usually unpleasant, impression from ordinary excitations. It may also be said that hyperaesthesia exists as a purely subjective state, psycho-sensory hyperaesthesia, without external mechanical excitations.

Hyperaesthesia of common tactile sensibility in the skin and mucous membranes is frequent. The least touch is felt with unpleasant acuteness and causes unusual reactions of a reflex order; frequently, but not necessarily always, a sensation of pain is produced at the same time. It has been claimed that in certain cases the points of the aesthesiometer could be perceived at smaller distances than the average normal, but I have never been able to demonstrate this to my satisfaction. The simplest form of tactile hyperaesthesia is met with in persons of a highly nervous organization, in those under the influence of strong emotions, in the hypnotic state, and while intoxicated. The common pathological conditions in which increased sensibility is found are meningitis , hydrophobia, tetanus, neuritis, dermatitis, hysteria, and spinal irritation; also in connection with inflammations and traumatisms.

Hyperalgesia, often coinciding with , is that condition in which pain is produced by excitations so slight that they would not affect a healthy nervous apparatus: it is commonly designated as tenderness. Acute and dull, superficial and deep tenderness should be sought for and distinguished, as having different values in diagnosis. A type of deep tenderness is that found upon pressing steadily upon a diseased nerve-trunk. Acute superficial hyperalgesia is best studied in cases of trigeminal neuralgia and spinal irritation. Occasionally, universal hyperalgesia is met with, usually in hysterical women.

Hyperaesthesia to thermal impressions is ordinarily shown with reference to cold. In cases of neuralgia or neuritis cold is felt excessively and painfully; in some cases of posterior spinal sclerosis there is the greatest dread of draughts of cold air, and patients protect their legs in an extraordinary manner.

Hyperaesthesia of the muscular sense. The special sensations or notions of muscular states and activities which we possess may be considerably exalted, as shown by greater delicacy and rapidity of movements, and by the abnormally acute way in which perceptions of form and dimensions are obtained by the subject without assistance from other senses. Examples of this condition are met with in hysteria and hypnotism.

Visceral hyperaesthesia is chiefly shown by abnormal consciousness of the presence and action of an organ. Visceral pain usually accompanies this, and is the more prominent symptom.

Increased reflex actions rarely fail to accompany hyperaesthesia in its various forms. In the hypnotic exaltation of muscular sense remarkable psychic effects may be induced, partly in a reflex way, but perhaps chiefly through the law of association.

PARAESTHESIAE are sensations which arise centrally in nerve-fibres or nervous centres, and are projected outward and referred to the periphery or surface by consciousness, in obedience to the general law of outward projection of sensations in the Ego. They may be produced by external agencies or arise centrally without demonstrable cause. Their number and variety are very great, varying somewhat with the descriptive powers and self-consciousness of the patient, the chief being pain, formication, numbness, coldness and heat, constriction and distension, malposition, imaginary movements, etc. etc.

Pain, the most distinct and frequent of paraesthesiae, is by most authors classed as a hyperaesthesia, yet a careful analysis will show the difference. Pain and hyperaesthesia often coexist and are inseparable, yet in a large proportion of cases of nervous diseases the former sensation occurs independently, sometimes in regions where absolute anaesthesia exists , and even apparently in lost parts . We are consequently justified in considering most pains as paraesthesiae. Pain assumes many forms, some real and typical, others as various as the lively imagination of nervous patients can make them. Thus we have sharp, cutting, darting pains in neuralgia, posterior spinal sclerosis, etc.; aching, throbbing, pounding pains in cephalalgia, inflammatory and traumatic conditions; boring, crushing, distending, constricting, burning pains, etc. etc. In some cases the sensation is only semi-painful, and more akin to paraesthesia .

Numbness, formication, etc. occur in a vast number of nervous affections--in cerebral and spinal organic lesions, in neuritis, in toxic conditions, and in neuroses. The distribution of paraesthesiae is a valuable index to the seat of the lesion.

Cutaneous itching and prickling may occur independently of any other skin lesion, constituting true or nervous prurigo. This may be universal and last for years.

Paraesthesiae of pressure are felt either as expansive or constrictive. The part appears swollen to consciousness, or it seems to be tightly compressed. Both these sensations are often felt about the head in a variety of pathological states, and an absurd and dangerous fashion has arisen of looking upon a sense of fulness in the head as indicative of hyperaemia. The sense of constriction may show itself around one toe, a leg, the trunk, around the neck, etc.; it may be narrow, like a cord, or broad and extensive, like a stocking or corset. Sometimes it is localized, and likened to the grasp of a hand or a spot-pressure. Not infrequently, especially in cases of paraplegia, the sensation of pressure is combined with subjective cold, the legs feeling as if tightly encased in ice.

Subjective sensations of heat and cold are often of the strongest kind, and are very distressing. A part whose real objective temperature is normal may appear to the patient's consciousness as icy cold or burning hot, even to the degree of apparent contact of fire . We observe such sensations in posterior spinal sclerosis, myelitis, neuritis, injuries to nerves. In some functional cases complaint is made of patches of hot or cold skin, not relieved by cold or heat.

Odd sensations, such as rolling or longitudinal motion of something under the skin, general or local throbbing, coition movements, are described, especially in functional or hysteroid cases.

Sensations of hunger, thirst, dyspnoea, defecation, micturition, the sexual feeling, may all appear in an abnormal or unprovoked manner, and are to be classed as visceral paraesthesiae. An important paraesthesia of this variety is met with in cases of hypochondriasis and melancholia; it is a sense of indescribable distress, with constriction, usually at the epigastrium and about the heart--the precordialangst of the Germans, or, as we would term it, praecordial anguish.

Paraesthesiae of the muscular sense occur. The subject has a feeling as if a part were lying in an unnatural position, or as if it were being pulled or twisted in various ways, and he is sometimes obliged to assure himself by the use of sight and by tactile examination that the sensation is illusory.

Hallucinatory paraesthesiae are those which are so well defined and strong as to need the aid of other senses and reasoning to convince the patient of their unreality. A peculiar example of this is what occurs after amputation of a limb: for days or weeks the lost member is felt with the utmost distinctness; the absent fingers or toes may be moved in imagination and their position described.

In hypochondriasis many of the symptoms complained of are nothing but paraesthesiae exaggerated by a morbid state of the mind, and sometimes created by expectant attention. The hallucinations of the insane are in great measure phenomena of this group, the projections, though special and common, never being so strong and definite as to acquire apparent objectivity.

The aurae of epilepsy are paraesthesiae. For example: a sensation in the epigastrium preceding a fit indicates an irritation at the origin of the vagus nerve and its projection as a subjective sensation at the distribution of the nerve. An auditory or visual aura similarly represents a discharge or projection from the acoustic and visual cortical areas respectively.

In most cases of malingering, and in some cases of so-called railway spine, the symptoms so loudly complained of belong to the two classes of hyperaesthesiae and paraesthesiae; they are undemonstrable and non-measurable; only the patient himself can vouch for their reality. A diagnosis in such cases, without objective symptoms indicating well-known lesions, should be very reserved.

ANAESTHESIA, or loss of sensibility, may exist in every degree, from one so slight as to be hardly demonstrable by delicate tests to the most absolute loss of all feeling. It manifests itself in various modes corresponding to the normal physiological varieties of sensibility; in most cases the loss of feeling involves all of these, but in others they are separately affected, and we observe the following types, pure or combined:

Tactile Anaesthesia. The capacity to perceive superficial and gentle impressions upon the skin and mucous membrane, and the ability to locate and separate such impressions, may be lost, while other modes of sensibility remain normal.

Analgesia is that condition in which painful impressions are not perceived, though common, caloric, or muscular sensibility may be normal or nearly so. Pricking, cutting, and bruising are unperceived. This, the most common variety, is usually met with in hysterical cases; it occurs at a certain stage of general artificial anaesthesia, in chronic alcoholism, extreme emotional states, and in hypnotism. Though a very striking symptom, it is not one of as serious meaning as loss of tactile or thermic sensibility. Often the patient is unaware of analgesia until tests reveal its existence.

The sensibility of the skin to caloric is usually the last to disappear in the progress of an organic lesion, so that in certain cases testing by ice or by a burning object is a sort of last resort. Before deciding in a given case that there is a complete break in the sensory tract, this test should be used as well as the application of the most intense induced electric current delivered upon the dry skin by a wire end.

In some cases of partial anaesthesia cold may be felt as heat and vice vers?, or pinching may be felt as burning, and be quite persistent.

The so-called muscular sense may be greatly impaired or lost without ordinary anaesthesia. In such a case the subject is no longer directly and spontaneously aware of the exact position of his limbs, of passive motions done to them, and he executes voluntary movements with uncertainty. He is also unable to judge correctly of differences of weight in objects successively placed in his hand or hung from his foot. He needs the aid of sight to guide the affected limb and to judge of its position, etc. The awkwardness and uncertainty in voluntary movements by impairment of muscular sense must not be confounded, as is sometimes done, with ataxia, in which the attempted volitional movement is jerky and oscillatory, owing to the inharmonious action of antagonistic muscular groups.

When a strong induced electrical current is passed through a muscle by means of wet electrodes applied to the skin, so as to cause a strong contraction, a special quasi-painful feeling, akin to that of cramp, is experienced in the contracting muscle, and is clearly distinguishable from the cutaneous sensation. This, the electro-muscular sensibility, may be lost independently of other modes of feeling and without loss of contractile power.

Some observers claim that a special mode of sensibility exists in the skin by which varying degrees of pressure are estimated, independently of traction upon tendons and muscles , and that this may be separately impaired or lost.

Visceral anaesthesia shows itself in the ordinary way by loss of that feeble degree of common sensibility which the internal organs possess, and also by impairment of their special functions, giving rise to anorexia, hydroadipsia, retention of feces and urine, loss of sexual feeling . Of course, these symptoms may be due to other conditions, and each case must be carefully studied. In the insane, visceral anaesthesia gives rise to delusions of emptiness, destruction of organs, and even, if coinciding with general cutaneous anaesthesia, to the notion that the body is dead or absent.

A singular phenomenon often witnessed is retardation in the transmission of an impression . Thus, in testing the sensibility of the skin of the legs in tabetic patients, it is observed that instead of the normal, almost instantaneous, appreciation of the impression made by a needle-point, there is a lapse of two, five, ten, or even sixty seconds between the pricking and the signal of sensation by the patient. It should always be determined in such cases whether the retardation is peripheral and actual, or central and due to psychic conditions . Thus, in a case of profound melancholia we may observe extreme slowness and dulness of sensory impressions or complete anaesthesia; but the symptoms would have a very different significance, diagnostic and prognostic, from the same noted in a mentally clear patient.

That a similar pathological condition occurs in the cerebral mechanism, and may serve to explain many psychic symptoms, is very probable.

On the other hand, a destructive lesion may be so placed in the spinal cord or brain as to allow centripetal impressions to reach healthy spinal gray matter in the normal way, but preventing their passage frontad to be recognized by consciousness. In such a case we observe normal, or more commonly exaggerated, reflex action in parts which are insensible in the ordinary sense of the term. Indeed, in many cases the disconnected caudal portion of the spinal cord is in a state of vastly exaggerated reflex activity, as shown by the tetanoid and convulsive involuntary and reflex movements which take place in completely paralyzed and anaesthetic limbs . In general terms, it may be stated that when anaesthesia is due to lesions of peripheral nervous endings, of nerve-trunks, and of the posterior root system of the spinal cord, reflexes are diminished or lost.

It is often stated that anaesthesia causes ataxia of movement. This, from the results of experiments on animals and from clinical study, we believe to be a gross error. In animals and in man loss of sensibility gives rise to awkwardness or uncertainty in movement which is properly to be classed as a special variety of inco-ordination; but it is not from ataxia, in which irregular, jerky, oscillating motions occur when a volitional act is attempted, these movements resulting from want of harmony in the action of antagonistic muscles which in the normal educated state automatically act together to produce the desired result. Besides, we occasionally observe cases of typical spinal ataxia in which no impairment of sensibility can be observed.

THE TOPOGRAPHICAL DISTRIBUTION of alterations of sensibility requires careful determination in practice, as from it we obtain most valuable aid in diagnosis. The following are the principal types observed:

Alterations of sensibility in one lateral half of the body and head. We thus have hemihyperaesthesia, hemiparaesthesia, or hemianaesthesia, and the special senses on one side are frequently involved. This clearly hemi-distribution indicates that the lesion or functional disorder is in the cerebral hemisphere of the opposite side, more especially in the caudal segment of the internal capsule or in its areas of cortical distribution . The distribution of hemianaesthesia, etc. from organic disease in these parts is identical with that observed in some functional cases; we can make the diagnosis only by the help of other data.

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